class Student:
    def __init__(self):
        print('构造方法1被调用！')
        self.name='Unknown'
    def __init__(self,name='Unknown'):
        print('构造方法2被调用！')
        self.name=name
    def SetName(self,newname):
        self.name=newname
    def PrintName(self):
        #print('姓名：%s 年龄：%s'%(self.name,self.__id))
        print('姓名：%s' % self.name)
if __name__=='__main__':
    stu1=Student()
    stu2=Student()
    stu3=Student('王五')
    stu1.SetName('张三')
    stu2.SetName('李四')
    stu1.PrintName()
    stu2.PrintName()
    #stu1._Student__id='hello'
    #print(stu1._Student__id)